Puerto Rican duo Calle 13–aka vocalist Residente (René Pérez Joglar) and multi-instrumentalist and producer Visitante (Eduardo José Cabra Martinez)–are invariably linked with reggaeton, but even on their self-titled 2005 debut they refused to be boxed in by the genre’s limitations. Their music has ranged freely, not just borrowing from hip-hop but vividly coloring Visitante’s production with tropical styles like cumbia and son.

The duo took a huge leap on its second album, Residente o Visitante (Norte, 2007), borrowing from collaborators like Orishas (Cuban trova) and the Bajofondo Tango Club (electro-tango) as well as raising the stakes with bits of bossa nova. And Residente’s Spanish-language lyrics started looking beyond straight-up raunch to deal with immigration and cultural identity.

The group returned with Los de Atrás Vienen Conmigo (“The Ones Left Behind Are Coming With Me”) last October, but despite the short turnaround time from their previous disc it wasn’t a quickie cash-in–easily one of the most original and riveting albums I heard last year, it took Calle 13’s game to even greater heights.

On the album’s first single, “No Hay Nadie Como Tú,” they partnered with excellent Mexican rock band Café Tacuba for a catchy hit that used a two-beat norteño groove and ended up sounding like Manu Chao; on “La Perla” they coaxed Panamanian legend Ruben Blades into singing and rapping a few verses. Though the beats are thoroughly electronic, many of the tracks feature a fat brass section, whose sound carries whiffs of New Orleans, Cuba, and even the Balkans. Calle 13 also mix in bits of Afrobeat, the lesser-known Argentine cumbia villera, and even old-school freestyle.

Yet just listing all the elements that go into this material is kinda missing the point–it risks making Calle 13 sound like dilletantes, when in fact their voracious musical appetites are all about having a good time and following their curiosity wherever it leads. Residente has such a distinctive flow that he sounds like himself no matter what the setting, and in his dense wordplay he likes to talk about how crazy he is–a perfect fit with the funny, breathless patchwork of the tracks.

The full Calle 13 lineup, which typically includes around a dozen musicians, plays a free, all-ages show tomorrow night at Metro sponsored by MySpace.com. You need to jump through a few annoying hoops to get in, and admission is first come, first served.

Today’s playlist:

Waed Bouhassoun, A Voice for Love (Institut du Monde Arabe)
Cheap Time, Cheap Time (In the Red)
Ali Ahmad Hussain Khan, Shenai 2 (Sense World Music)
Ba Cissoko, Séno (Sterns)
Leo’s Five, Direct From the Blue Note Club, East St. Louis (Ace)